Silyl Radicals by Reverse and One-Electron Electrochemistry

摘要

Silicon-centered radicals R_3Si~·, both as short-lived intermediates and as persistent species, were produced by means of electrochemistry. The one-electron electrochemical oxidation of silyl anions prepared by various methods (sonochemical cleavage of disilanes with K, reductive electrochemical titration of monochlorosilanes and by reverse electrochemistry in a flow-through cell) resulted in R_3Si~· radicals, which were involved in radical silylation of double bonds or trapped with PTBN as shown by EPR-spectroelectrochemistry. The same radical species were produced by oxidation-reduction of hexaphenyldisilane in a flow-through two-compartment cell. The possibility of generating silyl radicals by direct one-electron cathodic reduction has been demonstrated.